In the field of glass bonding, there is a need for a bonding agent, and particularly a primer, which can be used under a range of conditions. One desired function of the bonding agent is to treat the glass surface to ensure a tenacious bond between the glass and sealant (e.g., adhesive). In one application, adhesive or other sealant will be applied shortly after the bonding agent is applied. In other applications the adhesive or other sealant is applied after a considerable period of time has elapsed. It is important in all of these applications that the bonding agent is functional at the time when the adhesive or sealant is applied. It is common to refer to the useful pot life of the bonding agent as its open time. This generally refers to the time between initiation of polymerization of the bonding agent and the time at which an adhesive or other sealant can no longer be applied to the bonding agent and used optimally for bonding. For present glass bonding purposes (particularly for automotive applications), generally, optimum bonding use requires that the failure mode of the adhesive or other sealant to the bonding agent be predominantly cohesive, and more specifically, substantially entirely cohesive.
For example, it is common in one component primers to have an open time that is shorter than 20 seconds. Thus, to help assure that the failure mode of the adhesive or other sealant to the bonding agent is substantially entirely cohesive, the application of the adhesive or other sealant to the bonding agent should occur within 20 seconds of bonding agent application. For a long open time primer, typically a two component material, an elapsed time between application of primer and application of adhesive thereto typically may exceed 90 days. Unfortunately, many two component primers require additional steps labor and handling.
Examples from the literature addressing primer materials in this field include Published U.S. Patent Application Nos. US20010041782A1, 20030100676A1; U.S. Pat. Nos. 5,010,202; 4,874,805; 4,396,681; 4,367,313; 6,875,470; EP Patent No. 1217049A1; JP Patent Application Publication Nos. JP2003-336008, JP2003-128988, JP2002-309182, and JP2002-309163, all of which are hereby expressly incorporated by reference.